I want to make a point of sales and I have a raspberry pi that I want to make a posbox.
What version of Odoo that I should use ? What are my needs? How do I make it? Can someone help me?
Please teach me.
Thank you,

You'll need to do it along these lines:
1. Install Odoo 8 on a VM/VPS/Server/... (see my answer at https://www.odoo.com/forum/help-1/question/how-to-install-stable-debian-ver-of-odoo-8-in-ubuntu-14-04-lts-64581)
2. Activate the technical features of the admin user under settings > users. With this you'll get a lot more options.
3. Install the modules you need (Point Of Sale for sure)
4. Activate the ability to weigh products (Settings > sales) and check the option ' Allow using different units of measure'
5. Install 'Weighting Scale Hardware Driver'.
6. Go to the point of sale and open your 'Points of sales' and check the eletronic scale option (atleast, if you'll use it)
7. Setup your POS (Raspberry PI) and test it by start a Point of Sale session.

This is pretty much the step by step explanation.. if you need more details to ask as there are a LOT of options to explain here.
Good luck!

Connect the raspberry pi to your computer, add a ticket printer to your raspberry pi and you'll get a ticket with an IP. From there on you can check through the webinterface what the status is of your posbox and from all attached items (printer, scale, ...).
If this all looks fine you can add the posbox to your Odoo by installing the modules you'd like (scale driver), you can read more about the posbox here: https://doc.odoo.com/trunk/hw_proxy/

I have read about posbox,
post device is a computer, right?
there is written that I have to connect the PosBox to the Local Network with the RJ45 Cable. and make sure the PosBox connect to the same network as your POS device
what the purpose of it? networks such as what should I use?

about your answer at https://www.odoo.com/forum/help-1/question/how-to-install-stable-debian-ver-of-odoo-8-in-ubuntu-14-04-lts-64581, I have to manual installation without auto-start on my computer, and Automatic install script with automatic booting after startup on my raspberry is it right ?

You'll need to connect your raspberry pi to the same network as your computer, both the PC with Odoo and the Raspberry Pi with an RJ-45 cable. The choice of the default installation (no auto-start) or the auto-start version is yours. The benefit of the auto-start is that you'll never need to bother with starting up Odoo etc. I'm not sure what you mean with installing the automatic booting on your raspberry pi.. the only thing that should be on your raspberry pi is the posbox image, nothing else.

Ofcourse I can help you. You should follow this tutorial, it works great, I've used it twice before too. http://elinux.org/RPi_Easy_SD_Card_Setup#Flashing_the_SD_Card_using_Windows
By the way, if my answers are good and valid please also accept the answer besides of upvoting it. This will tell other users its a valid, good working, solution.

The picture is the http:// link, just paste it in a new tab. Your next step is to get yourself is to install the drivers and then configure everything for the POS on your Odoo. I presume you'll use a weighing scale so also install the scale driver.